Material for gland packing and the gland packing

Abstract

A reinforcing member made from a fibrous material and disposed at least on one face of a strip-like expanded graphite to form a strip-like base member. The base member is stranded to be formed as a cord-like member. At this time, one side end edge of the base member is placed on the outer peripheral surface of the cord-like member, and, in the side end edge, the strip-like expanded graphite is more elongated in the width direction than the reinforcing member. The stranding of the base member is applied while the strip-like expanded graphite which is elongated in the width direction is placed on the inner side, and the reinforcing member which is short in the width direction is placed on the outer side. According to the configuration, both the reinforcing member and the strip-like expanded graphite are placed in a spiral manner to be alternately arranged in the axial direction on the outer peripheral surface of the cord-like member.

1. A gland packing material wherein said gland packing material comprises a cord member ( 40 ) which is formed by stranding a base strip member ( 4 ), or winding a base strip member ( 4 ) about a longitudinal direction; or winding a base strip member ( 4 ) about a longitudinal direction and then stranding said base strip member,
 said base strip member ( 4 ) comprises: a reinforcing member ( 20 ) comprised of a fibrous material ( 2 ); and an expanded graphite strip ( 3 ), 
 said reinforcing member ( 20 ) is disposed at least on one face of said expanded graphite strip ( 3 ), and 
 both said reinforcing member ( 20 ) and said expanded graphite strip ( 3 ) are placed on an outer peripheral surface of said cord member ( 40 ). 
 
   
   
     2. A gland packing material according to  claim 1 , wherein one side end edge of said base strip member ( 4 ) is placed on an outer peripheral surface of said cord member ( 40 ) in the side end edge, one member ( 4   a ) of said reinforcing member ( 20 ) and said expanded graphite strip ( 3 ) is more elongated in a width direction than another member ( 4   b ), and
 said one member ( 4   a ) which is elongated in the width direction is placed on an inner side, and said other member ( 4   b ) which is short in the width direction is placed on an outer side, said base strip member ( 4 ) is stranded after said base strip member is wound about the longitudinal direction, whereby said reinforcing member ( 20 ) and said expanded graphite strip ( 3 ) are placed in a spiral manner to be alternately arranged in an axial direction on the outer peripheral surface of said cord member ( 40 ). 
 
   
   
     3. A gland packing material according to  claim 1 , wherein said reinforcing member ( 20 ) is formed to be smaller in width than said expanded graphite strip ( 3 ),
 a plurality of said reinforcing members ( 20 ) are disposed at least on one face of said expanded graphite strip ( 3 ) with intervals formed therebetween in a width direction, and 
 said smaller in width reinforcing members ( 20 ) are placed on an outer side, said base strip member ( 4 ) is stranded alter said base strip member is wound about the longitudinal direction, whereby said reinforcing members ( 20 ) and said expanded graphite strip ( 3 ) are wound in a spiral manner to be alternately arranged in an axial direction on the outer peripheral surface of said cord member ( 40 ). 
 
   
   
     4. A gland packing material according to  claim 1 , wherein said base strip member ( 4 ) is stranded after said base strip member is wound about the longitudinal direction in an intermediate portion in the width direction of said base strip member ( 4 ), thereby causing both side end edges of said base strip member ( 4 ) to be positioned on an outer peripheral surface of said cord member ( 40 ),
 in one of said side end edges, said reinforcing member ( 20 ) is placed on an outer side, and, in another side end edge, said expanded graphite strip ( 3 ) is placed on an outer side, whereby said reinforcing member ( 20 ) and said expanded graphite strip ( 3 ) are placed in a spiral manner to be alternately arranged in an axial direction on the outer peripheral surface of said card member ( 40 ). 
 
   
   
     5. A gland packing material according to  claim 1 , wherein said reinforcing member ( 20 ) is placed on the outer peripheral surface of said cord member ( 40 ),
 a large number of openings ( 20 A) are formed in said reinforcing member ( 20 ), 
 said expended graphite strip ( 3 ) enters said openings ( 20 A), and is exposed from the outer peripheral surface of said cord member ( 40 ) through said openings ( 20 A). 
 
   
   
     6. A gland packing material according to  claim 1 , wherein said reinforcing member ( 20 ) is disposed only on one face of said expanded graphite strip ( 3 ). 
   
   
     7. A gland packing material according to  claim 1 , wherein said reinforcing member ( 20 ) is disposed on both faces of said expanded graphite strip ( 3 ). 
   
   
     8. A gland packing material according to  claim 1 , wherein said fibrous material ( 2 ) is fanned into a sheet shape, and said fibrous material sheet comprises a fiber-opened sheet ( 2 B) in which multifilament yarns are opened in a sheet shape. 
   
   
     9. A gland packing material according to  claim 8 , wherein a thickness of said fiber-opened sheet ( 2 B) is set to 10 μm to 300 μm. 
   
   
     10. A gland packing material according to  claim 1 , wherein said fibrous material ( 2 ) comprises at least one selected from the group consisting of carbon fibers, brittle fibers, and tough fibers. 
   
   
     11. A gland packing material according to  claim 10 , wherein said brittle fibers comprise at least one selected from the group consisting of glass fibers, silica fibers, and ceramic fibers. 
   
   
     12. A gland packing material according to  claim 10 , wherein said tough fibers comprise at least one selected from the group consisting of metal fibers, aramid fibers, and PBO fibers. 
   
   
     13. A gland packing comprising braiding or winding together a plurality of gland packing materials ( 1 ) according to any one of  claims 1  to  12 .